Downpipe Related, ways to prevent CEL?

[Bakis]

Ok guy's for the time being im not going to purchase a Downpipe, im just going to try and modify the CATs in the Standard one.

Correct me if im wrong but the second CAT (further away from Turbo) isn't monitered by a O2 Sensor, and if i remove with a Race Pipe shouldn't cause a CEL?

I know 'grey alex' premhk has done this and he hasn't got a CEL so im sure that well work.

As for the First Cat, i dont wanna run catless but if i get an exhuast shop to replace with a 100CPI or a 150CPI car what are the risks of receiving a CEL? I know the BM downpipes has a 100CPI CAT at the end of it and that guaranteed no CEL.

Question is what do i have to do if i want to replace the first cat with a better flowing one and not receive a CEL?

All help is appreciated

[Reedy]

You're right about the second cat not being monitored, but from all reports these days the new DP upgrades have fixed the CEL issue, it was only the early ones that caused problems. New ones re use the sensor and if installed properly, shouldnt give a CEL.

[2XS]

Ok guy's for the time being im not going to purchase a Downpipe, im just going to try and modify the CATs in the Standard one.

Correct me if im wrong but the second CAT (further away from Turbo) isn't monitered by a O2 Sensor, and if i remove with a Race Pipe shouldn't cause a CEL?

I know 'grey alex' premhk has done this and he hasn't got a CEL so im sure that well work.

As for the First Cat, i dont wanna run catless but if i get an exhuast shop to replace with a 100CPI or a 150CPI car what are the risks of receiving a CEL? I know the BM downpipes has a 100CPI CAT at the end of it and that guaranteed no CEL.

Question is what do i have to do if i want to replace the first cat with a better flowing one and not receive a CEL?

All help is appreciated

Have the first cat removed completely, good luck finding any exhaust shop to do that for a reasonable price,
Next, have the 2nd Cat replaced with a quality 200 Cpi one,
Last, have the 2nd O2 sensor extended behind the now first Cat.

Pending any issues, You can use an O2 sensor extension.



NOTE: 100 Cpi cats are illegal Aust wide.
NOTE: Removing 2 cats and replaceing it with 1 item is illegal in NSW (Pending an engineers cert.) Vic is similar in Laws to NSW.
NOTE: You may even need a Euro 4 cat to get away with 1 Cat in NSW

[Bakis]

Thanks troy the legal thing doesn't fuss me much but ill see how I go. Just to put it out there if I wanted the 100cpi cat would there be any issues with this over a 200cpi? Or is the flow difference not even worth it?

I'll find prices then way up options thanks guys

[2XS]

If you are still running the std DP, but just replacing the cat, the benefits would be lost everywhere else in the setup.

I highly doubt you would see any gains in performance getting a 100 cpi over a 200 cpi in a std to mildly modded MPS.

Gees, a highly modded XR6 turbo only sees +2-3Kw @ wheels from 200 cpi to no Cat at all.

[Yeldarb]

Well, I still have CEL's with my BM DP. I love it, don't get me wrong, just a bit peeved nothing seems to have been done about it.

The CEL seems to give me a very rich mixture. My tail pipes are always black and I wash the car weekly. The car sounds different too, probably the extra fuel burning off or something.

Go the DP man. You will not regret it.

[Bakis]

If you are still running the std DP, but just replacing the cat, the benefits would be lost everywhere else in the setup.

I highly doubt you would see any gains in performance getting a 100 cpi over a 200 cpi in a std to mildly modded MPS.

Gees, a highly modded XR6 turbo only sees +2-3Kw @ wheels from 200 cpi to no Cat at all.

Thank's Troy cleared the waters for me . I think i'll copy premhk and what he did he made about 75% of the gains from gutting a cat of which ppl have made from installing a DP/

This is the course of action atm cause i finish uni at the end of next year and might be going on a holiday after it with mates and depending where on the east coast might either drop in at 2XS or BM for a downpipe .

[Nirvandan]

might either drop in at 2XS or BM for a downpipe .

Its a no brainer, 2XS.

[Reedy]

Time to revive this thread.

I have had a Cp-e DP for 9 months now and got my first cat related CEL (P0421 Warm up cat efficiency below threshold)

Scenario:
2010 Gen II MPS
Cp-e DP
ECUTEK tuned
Car had been tracked the day before
CEL came on shortly after filling up on the highway on the way home from brisbane.
TH installed an O2 sensor extension and cleared the code, but it came back again the day after.

Possible causes:
Track day? If anything is going to cause problems it's tracking the car. I have tracked it a handfull of times before without any issues. Wth the amount of smoke my car blows it wouldnt surprise me if the CAT has become fouled.

Dodgy batch of fuel? It came up after I filled up, coincedence? possible? I have since finished off that tank and filled up again so will see what happens once I clear this second code.

CAT is blocked/fouled? I read somewhere that you can pop the car in neutral and run it at 4000rpm for a minute solid to burn off built up carbon in the cat? is this internet bullshit or can it actually help? If not will I need to get a new cat to fix this issue? Any other way of renewing a CAT?

[Cton]

It would be a huge pain in the ass to change the cat on the cp-e downpipe. I know Matt had a Cpe downpipe that had a cat that had crapped itself.
It's strange to get the cat efficiency code with the Cp-e, being that the sensor is after the cat.
Maybe it's crapped itself totally? I guess there is no way find out without removing the DP though.